The lionfish is considered to be one of the strangest and most spectacular members of the fauna that inhabits coral reefs. The highly developed fins, which have long rays, the slender, twisted spines that embellish the body with the brightest of colors, and the disproportionately large mouth, all give this fish an appearance that is somewhat grotesque.

Like the other scorpionfishes, lionfish is common throughout the Indo-Pacific region, but it does not occur in the eastern Pacific. Unlike most scorpionfishes, which have perfect camouflage, the lionfish contrasts dramatically with its habitat. It is a fish that is happiest in shallow, warm waters, where young specimen live in large numbers. Very young individuals are more or less transparent.

This fish can also be found in estuaries. During the daylight hours, Pterois volitans keeps close to rocky outcrops, hiding beneath rocks or in small grottoes and recesses. At twilight it emerges from its hideout and starts hunting deeper down, on the sand or coral. The prey include crabs, shrimps, and fish. It does not catch nonmoving prey on the sea bed, but it can remain motionless, "suspended" in open water or positioned in front of its prey, waiting for it to make the slightest movement. Like the other members of the family, it has a huge mouth that enables it to catch prey the same size as itself. The lionfish lays its eggs enveloped in a mass of mucus that enables them to float and become dispersed by the action of the wind and the currents. This is a very prolific fish.